Hi Liam,
I was about to post, then saw that Nikki had very much taken the words out of my mouth. Like her, I'm sorry to be a bit blunt, but it's perfectly true that even if you had drawn the one-in-a-million short straw there'd be nothing you could do about it anyway as there's no cure. (This is the actual estimated incidence of CJD worldwide, not something I pulled out of a hat.)
In fact it's highly unlikely that CJD would present initially with muscle twitches. In the vast majority of cases it starts quite abruptly with mental changes - severe memory loss (as opposed to absent-mindedness induced by anxiety), aggressive behaviour, delusions (again, not delusional fears about one's health) etc.
You do not have CJD. Basically, all you need to do is wait a couple of weeks. If you did have it you'd already be seriously disabled by then, as it progresses very quickly. Most patients die within a few months, and it's unusual to survive even for a year.
However, as we've both said, it might be helpful to see your doctor just to get some reassurance, and preferably a referral for CBT. But be careful about medication. Some GPs are a bit trigger-happy in prescribing powerful antipsychotic drugs for quite minor anxiety or depression. As Nikki rightly says - and she's speaking from experience - these drugs can in themselves cause a neurological condition (though not CJD of course) and are best avoided unless you're suffering from a full-blown psychiatric illness.
In your current heightened state of anxiety it's quite normal that you're going to start noticing every tiny twitch or tingle. It's also likely that you're going to start hyperventilating. I used to do this during times of anxiety when I was young. It was only when I started training as a nurse that I figured out what was going on.
When we get anxious, many of us hyperventilate unconsciously. We breathe too deeply and/or too quickly, but without being aware that we're doing it. This "rinses out" too much carbon dioxide from the body, rendering the blood slightly too alkaline. This in turn causes electrolyte imbalances in the body, the symptoms of which are mild dizziness, brain fog, tingling sensations in the fingers and lips, stiffening of the fingers and - if it goes on for long enough - muscle twitches and jerks.
Alarming as all this sounds, it's perfectly harmless. Once things get bad enough the brain eventually steps in and sends our breathing back to normal. Same process as when you try to hold your breath - your brain won't let you damage yourself.
Make that appointment with your doctor and please stop surfing the net for possible diagnoses. You really don't have CJD or any other neuro-degenerative disease.